Process of making colored photographs.



emu nsonna, or srnomrz, NEAR BERLIN, (mummy.

PROCESS O l MAKING COLORED PHOTOGRAPHS.

No Drawing.

Specification of Letters Patent.

Application filed January 27, 1913. Serial No. 744,386.

Patented June 30, 1914.

T 0 all whom, it may concern:

Be it known that I, RUDOLF FISCHER, a citizen of the German Empire, and resident of Steglitz, near Berlin, Germany, have invented a certain new and useful Improved Process of Making Colored Photographs, of which the following is a specification.

The subject-matter of my invention 18 an improved process of making photographic pictures.

The development of photographic halogen-silver films leads, in general, to a black picture substantially composed of silver. Individual cases, are however, well known in which colored pictures can be obtained directly when developing. Thus, developing with pyrogallol yields a yellowish-brown picture, with indoxyl a blue, and with thioindoxyl a red picture. Also, the other customary photographic developers yield, under suitable conditions, e. g. absence of sodium sulfite and similar bodies, more or less colored pictures. The colors thus obtained are, however, either not very decided, or, as in the case of the developers from the indigo group. not readily obtainable. i

Now I have found that exceedingly highly colored pictures can be very readily obtained by not using the oxidation products of the developers alone, but by adding to the developers substances which become coupled with those oxidation products of the devel oper which are formed while developing.

and form colored bodies soluble with difficulty. According to the developers or coupling bodies which are employed I obtain representatives of various classes of coloring materials or dyes, of which the following are given as examples The bodies soluble with most ditiicultyare obtained with p-phenylenediamin as developer and phenols or compounds with acid methylene groups as coupling bodies.

The p-phenylenediamins comprise the side chains homologues and core homologues,

p-amidophenols p-phenylenediamins 'nitrile,

also the substitutes of p-phenylenediamin in the amidogroup or in the core.

Examples :p-pl1enylenediamin, p-toluylenediamin, amido-p-phenylenediamin, chlorp-phenylenediamin, monoethyl-p-phenylenediam-in, diinethyl-p phenylenediamin. Further, the amidogroup may be included in a ring system: p-aminophenylene-piperidin.

By phenols, likewise, the side chains and core homologues and the substitution products are to be understood.

Example: phenol, cresol, naphthol, oainidophenol, trichlor-naphthol, resorcinmethyl-ether, na-phthol-sulfonic acid.

The acid methylene compounds may be both of an aliphatic and also of an aromatic nature.

Examples: ethyl-aceto-acetate, malonochloraceto-phenone, diketohydrindene, nitrobenzyl-cyanid, thioindoxyl.

Further, the methylene group may be substituted when the substitute is split during -the reaction.

Examples: chlor-ethyl-aceto-acetate, thioindoxyl-carboxylic acid.

The coloring matter or dye produced in these processes of development can be reduced to leuco compounds which likewise possess developing properties and likewise yield colored pictures directly during the developing process when the ozidation products are soluble with difliculty. Here also it is found that the above specially mentioned classes of coloring materials yield the best results. The developing properties of a part of these classes are already known; for ex ample, the developer 'pyramidol i. e. dioxydiphenylamin is a leuco-indophenol. Nevertheless, only black pictures were obtained, and it was not observed that colored oxidation products soluble with such ditliculty could be obtained that colored pictures were obtained. It is preferable to omit the admixture of sodium sulfite or similar bodies. The employment of the leuco bodies is, however, not very preferable because they change readily. while the first described separate form of employment has the advantage that the components can be preserved separately and need be mixed only immediately before the development or when developing.

The colored developers can also be employed in such a form that they are incorpo rated in the film or the film-carrier. or a separate layer is applied to the layer or film sensitive to light. Either the leuco pounds, the separate components, or only one of the two may be used. The coloringmaterial picture can be isolated by removing the silver by means of one of the well-known agents which will lighten the picture.

- Examples.

- are added to the following solution :--hydrochlorid of p amidophenylenepiperidin, 40 g. soda, 100 cms. water. Blue picture.

3. 2 g. cz-naphthol dissolved in cms. acetone are added to the following solution:-2 g. hydrochlorid of dimethylparaphenylenediamin, g. soda, 1000 cms. water. Blue picture. I

4. 2 g. thioindoxyl-carboxylic acid dissolved in c. cms. acetone are added to the following solution and shaken well:-2 g. hydrochlorid of monoethylparaphenylenediamin, 40 g. potash, 1000 cms. water. Red picture. I

5. 2 g. o-nitrobenzylcyanid in 20 'c. cms. acetone are added to a solution of 2 g.'hydrochlorid of dimethyl paraphenylenediamin 30 g. soda, 1000 cms. water..uBrownish-red picture. 1

6. 2 g. a-chlor-ethyl-aceto-acetate in 20 c. cms. acetone are added to 2 g. diethylparaphenylenediamin, 40 g. potash, 1000 ems. water. Yellowpicture.

7. 2 g. p-nitrobenzylcyanid in 20 c. cms.

acetone are added to 1 g. p-amidophenol, 40 g. potash, 1000 cms. water. Brown picture.

8. 2 g. tony-2 amido-'diethylamidodiphenylamin, g. potash, 1000 cms. water. Blue picture.

9. 2 4-dimethylamidophenyl-a-cyanazomethin-phenyl. 100 g. potash, 100 cms.

water. Orange-colored picture.

graphic pictures, consisting in deve oping pictures on halogen-silver films with the leuco compounds of a product resulting from the connection of a'developer with a substance which in connection with the oxidation product of such developer forms a colored body soluble with difficulty 3. A process of making colored, photographic pictures, consisting in developing pictures on halogen-silver films with a developer and a substance which in connection with the oxidation product of the developer forms a colored body soluble with dificulty, the substances giving the color being placed in the layer to be developed, substantially as described.

4.. A process of making colored, photographic pictures, consisting in developing pictures on halogen-silver films by aromatic diamins and aromatic hydroxyls.

5. A process of rmaking colored, photographic pictures, consisting in developing pictures on halogen-silver films by aromatic diamins and compounds containing meth-.

ylene groups of an acid character.

In testimony whereof, I afiix my signature in the presence of two witnesses.

RUDOLF FISCHER. Witnesses: v

WQLDEMAR HAUPT, HENRY HAsPnn. 

